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1.
Expert Rev Neurother ; 23(6): 525-534, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37231674

RESUMEN

INTRODUCTION: The experience of psychosis involves changes in an individual's sense of self and their understanding of others and the world around them. Studying life narratives and narrative identity offers one way to better understand these changes. AREAS COVERED: Narratives of persons with psychosis display alterations in their themes, structures, and processes. These narratives often portray the person as possessing relatively little sense of agency, without meaningful connections to others, and often describe events in a negative emotional tone. The structure of these narratives often lacks temporal cohesion, unfolding in a disjointed manner. The overall structure and content of narratives further appear to struggle to respond to experience, suggesting that individuals with psychosis may have difficulty incorporating new information into their narrative, leading to a lack of narrative evolution. This body of research illustrates how psychosis reflects the interruption of an unfolding life in which sense of self is compromised and cannot be understood as a collection of symptoms and skill deficits. EXPERT OPINION: There is a need for treatment to address disruptions in personal narratives among persons with psychosis to promote a sense of purpose, possibility and meaning. As our understanding of psychosis continues to evolve and we emphasize first-person life stories, the authors believe that stigma in providers will decrease and the importance of subjective recovery will be further revealed.


Asunto(s)
Trastornos Psicóticos , Humanos , Trastornos Psicóticos/terapia , Emociones
2.
J Int Neuropsychol Soc ; 22(6): 595-608, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27211109

RESUMEN

OBJECTIVES: Visuospatial processing deficits have been reported in Huntington's disease (HD). To date, no study has examined associations between visuospatial cognition and posterior brain findings in HD. METHODS: We compared 119 premanifest (55> and 64<10.8 years to expected disease onset) and 104 early symptomatic (59 stage-1 and 45 stage-2) gene carriers, with 110 controls on visual search and mental rotation performance at baseline and 12 months. In the disease groups, we also examined associations between task performance and disease severity, functional capacity and structural brain measures. RESULTS: Cross-sectionally, there were strong differences between all disease groups and controls on visual search, and between diagnosed groups and controls on mental rotation accuracy. Only the premanifest participants close to onset took longer than controls to respond correctly to mental rotation. Visual search negatively correlated with disease burden and motor symptoms in diagnosed individuals, and positively correlated with functional capacity. Mental rotation ("same") was negatively correlated with motor symptoms in stage-2 individuals, and positively correlated with functional capacity. Visual search and mental rotation were associated with parieto-occipital (pre-/cuneus, calcarine, lingual) and temporal (posterior fusiform) volume and cortical thickness. Longitudinally, visual search deteriorated over 12 months in stage-2 individuals, with no evidence of declines in mental rotation. CONCLUSIONS: Our findings provide evidence linking early visuospatial deficits to functioning and posterior cortical dysfunction in HD. The findings are important since large research efforts have focused on fronto-striatal mediated cognitive changes, with little attention given to aspects of cognition outside of these areas. (JINS, 2016, 22, 595-608).


Asunto(s)
Corteza Cerebral/fisiopatología , Enfermedad de Huntington/fisiopatología , Síntomas Prodrómicos , Percepción Espacial/fisiología , Percepción Visual/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
3.
Parkinsonism Relat Disord ; 21(8): 894-8, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26040709

RESUMEN

INTRODUCTION: The aim of this study was to investigate the feasibility of using two computer-administered neuropsychological tasks in a clinical trial involving participants with Parkinson's disease without dementia. The tasks, probabilistic reversal learning (PRL) and serial reaction time (SRT), target dorsolateral prefrontal cortex (SRT) and ventral striatal-orbitofrontal (PRL) functioning respectively. METHODS: Participants were 53 adults with idiopathic Parkinson's disease who completed both the SRT and PRL tasks at baseline in a clinical trial. Repeated measures were examined only for the placebo group (n = 20). RESULTS: No participants were removed from analyses due to inability to complete the tasks, and most had fewer than 10% of trials culled due to slow reaction times. Response accuracy on PRL was 81.98% and 66.65% for the two stages of the task respectively. Disease duration was associated with SRT relearning. Disease duration and stage were associated with initial learning on PRL, and there was a trend towards disease stage predicting greater errors on PRL. Among participants in the placebo group, practice effects were seen on PRL (Phase 1 errors) and SRT (relearning). CONCLUSIONS: These results provide initial evidence for the clinical feasibility of computerized PRL and SRT tasks in clinical trials in Parkinson's disease.


Asunto(s)
Ensayos Clínicos como Asunto/normas , Pruebas Neuropsicológicas/normas , Evaluación de Resultado en la Atención de Salud/normas , Enfermedad de Parkinson/diagnóstico , Aprendizaje por Probabilidad , Tiempo de Reacción/fisiología , Aprendizaje Inverso/fisiología , Anciano , Estudios de Factibilidad , Humanos , Masculino , Persona de Mediana Edad
4.
Mov Disord ; 29(10): 1281-8, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25209258

RESUMEN

Cognitive dysfunction is central to Huntington's disease (HD) and undermines quality of life. Clinical trials are now targeting cognitive outcomes in HD; however, no cognitive battery has been optimized for HD clinical trials. We evaluated 16 cognitive tests in a 20-site, five-country, observational study designed to mimic aspects of a clinical trial (e.g., data collection managed by a contract research organization, repeated testing, prespecified statistical analyses). Fifty-five early HD, 103 premanifest HD (pre-HD), and 105 controls were tested at visit 1, visit 2 (1-3 days later), and visit 3 (5-7 weeks after visit 1). For inclusion in a recommended battery, tests were evaluated for sensitivity, practice effects, reliability, domain coverage, feasibility, and tolerability. Most tests differentiated controls from pre-HD and early HD and showed excellent psychometric properties. We selected six tests to constitute the Huntington's Disease Cognitive Assessment Battery (HD-CAB): Symbol Digit Modalities Test, Paced Tapping, One Touch Stockings of Cambridge (abbreviated), Emotion Recognition, Trail Making B, and the Hopkins Verbal Learning Test. These tests demonstrated sensitivity to disease status (Cohen's d effect sizes: early HD= -1.38 to -1.90 and pre-HD= -0.41 to -0.78), and acceptable reliability (r's 0.73-0.93). A composite score yielded large effect sizes (early HD = -2.44 and pre-HD = -0.87) and high reliability (r = 0.95). HD-CAB is the first cognitive battery designed specifically for use in late premanifest and early HD clinical trials. Adoption of the HD-CAB will facilitate evaluation of treatments to improve cognition in HD.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Enfermedad de Huntington/complicaciones , Pruebas Neuropsicológicas , Adulto , Análisis de Varianza , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores de Tiempo
5.
J Neurol Neurosurg Psychiatry ; 83(7): 687-94, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22566599

RESUMEN

BACKGROUND: Deterioration of cognitive functioning is a debilitating symptom in many neurodegenerative diseases, such as Huntington's disease (HD). To date, there are no effective treatments for the cognitive problems associated with HD. Cognitive assessment outcomes will have a central role in the efforts to develop treatments to delay onset or slow the progression of the disease. The TRACK-HD study was designed to build a rational basis for the selection of cognitive outcomes for HD clinical trials. METHODS: There were a total of 349 participants, including controls (n=116), premanifest HD (n=117) and early HD (n=116). A standardised cognitive assessment battery (including nine cognitive tests comprising 12 outcome measures) was administered at baseline, and at 12 and 24 months, and consisted of a combination of paper and pencil and computerised tasks selected to be sensitive to cortical-striatal damage or HD. Each cognitive outcome was analysed separately using a generalised least squares regression model. Results are expressed as effect sizes to permit comparisons between tasks. RESULTS: 10 of the 12 cognitive outcomes showed evidence of deterioration in the early HD group, relative to controls, over 24 months, with greatest sensitivity in Symbol Digit, Circle Tracing direct and indirect, and Stroop word reading. In contrast, there was very little evidence of deterioration in the premanifest HD group relative to controls. CONCLUSIONS: The findings describe tests that are sensitive to longitudinal cognitive change in HD and elucidate important considerations for selecting cognitive outcomes for clinical trials of compounds aimed at ameliorating cognitive decline in HD.


Asunto(s)
Trastornos del Conocimiento/etiología , Enfermedad de Huntington/complicaciones , Adolescente , Adulto , Factores de Edad , Anciano , Progresión de la Enfermedad , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Índice de Severidad de la Enfermedad , Factores Sexuales , Factores de Tiempo , Adulto Joven
6.
J Huntingtons Dis ; 1(1): 97-106, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-25063192

RESUMEN

Working memory deficits have been found in Huntington's disease (HD) and in a small group of premanifest (PreHD) gene-carriers. However, the nature and extent of these deficits are unknown. In a large cross-sectional study, we aimed to determine the degree of visuospatial working memory dysfunction across multiple stages of HD. Specifically, visuospatial working memory capacity and response times across various degrees of difficulty were examined, as well as the relationship between visuospatial working memory and motor dysfunction. We examined 62 PreHD-A gene-carriers (>10.8 years from estimated disease onset), 58 PreHD-B gene-carriers (<10.8 years from estimated disease onset), 77 stage-1 HD patients (HD1), 44 stage-2 HD patients (HD2), and 122 healthy controls. Participants viewed coloured squares (in sets of 3, 5 and 7) on a screen and were to decide whether on a subsequent screen the encircled square has changed colour. Accuracy and response times were recorded. Compared to controls, significant group differences in visuospatial working memory capacity (accuracy) were seen in PreHD-B, HD1 and HD2 groups across the difficulty levels. Significant group differences on response times were found for all groups (PreHD-A to HD2) compared to controls; the most difficult level producing the only group difference in speed between PreHD-A and controls. Accuracy and speed were positively correlated only in the HD groups. These findings suggest that visuospatial working memory impairments are detectable in both premanifest and manifest HD; the manifest HD showed evidence for a "worse-worse phenomenon" whereby reductions were present in both motor speed and accuracy.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Enfermedad de Huntington/genética , Enfermedad de Huntington/fisiopatología , Memoria a Corto Plazo , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas
7.
Clin Neuropsychol ; 25(5): 757-77, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21660882

RESUMEN

Estimates of premorbid intellect are often used in neuropsychological assessment to make inferences about cognitive decline. To optimize the method of controlling for premorbid intellect in assessments of prodromal neurodegenerative disease, we examined performance on the American National Adult Reading Test (ANART; administered during Years 1 and 3) and the two-subtest version of the Wechsler Abbreviated Scale of Intelligence (WASI; administered in Years 2 and 4) in an ongoing prospective longitudinal study of 371 participants with prodromal Huntington disease and 51 participants with normal CAG repeats. Although both measures performed similarly, the ANART demonstrated slightly lower variability in performance over a 2-year period and had slightly higher test-retest reliability than the WASI.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Discapacidades del Desarrollo/fisiopatología , Enfermedad de Huntington/diagnóstico , Enfermedad de Huntington/psicología , Inteligencia , Adulto , Análisis de Varianza , Trastornos del Conocimiento/etiología , Femenino , Humanos , Enfermedad de Huntington/complicaciones , Enfermedad de Huntington/genética , Pruebas de Inteligencia , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Reproducibilidad de los Resultados , Expansión de Repetición de Trinucleótido/genética , Conducta Verbal
8.
Neuropsychology ; 25(1): 1-14, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20919768

RESUMEN

OBJECTIVE: PREDICT-HD is a large-scale international study of people with the Huntington disease (HD) CAG-repeat expansion who are not yet diagnosed with HD. The objective of this study was to determine the stage in the HD prodrome at which cognitive differences from CAG-normal controls can be reliably detected. METHOD: For each of 738 HD CAG-expanded participants, we computed estimated years to clinical diagnosis and probability of diagnosis in 5 years based on age and CAG-repeat expansion number (Langbehn, Brinkman, Falush, Paulsen, & Hayden, 2004). We then stratified the sample into groups: NEAR, estimated to be ≤9 years; MID, between 9 and 15 years; and FAR, ≥15 years. The control sample included 168 CAG-normal participants. Nineteen cognitive tasks were used to assess attention, working memory, psychomotor functions, episodic memory, language, recognition of facial emotion, sensory-perceptual functions, and executive functions. RESULTS: Compared with the controls, the NEAR group showed significantly poorer performance on nearly all of the cognitive tests and the MID group on about half of the cognitive tests (p = .05, Cohen's d NEAR as large as -1.17, MID as large as -0.61). One test even revealed significantly poorer performance in the FAR group (Cohen's d = -0.26). Individual tasks accounted for 0.2% to 9.7% of the variance in estimated proximity to diagnosis. Overall, the cognitive battery accounted for 34% of the variance; in comparison, the Unified Huntington's Disease Rating Scale motor score accounted for 11.7%. CONCLUSIONS: Neurocognitive tests are robust clinical indicators of the disease process prior to reaching criteria for motor diagnosis of HD.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Trastornos del Conocimiento/etiología , Enfermedad de Huntington/complicaciones , Enfermedad de Huntington/diagnóstico , Pruebas Neuropsicológicas , Adulto , Atención , Trastornos del Conocimiento/genética , Emociones , Femenino , Humanos , Proteína Huntingtina , Enfermedad de Huntington/genética , Cooperación Internacional , Lenguaje , Masculino , Recuerdo Mental , Persona de Mediana Edad , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Valor Predictivo de las Pruebas , Desempeño Psicomotor , Estudios Retrospectivos , Tamaño de la Muestra , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Factores de Tiempo , Repeticiones de Trinucleótidos/genética
9.
Neuropsychologia ; 49(2): 264-70, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21094653

RESUMEN

OBJECTIVES: Visuomotor integration deficits have been documented in Huntington disease (HD), with disproportionately more impairment when direct visual feedback is unavailable. Visuomotor integration under direct and indirect visual feedback conditions has not been investigated in the stage before clinical onset ('premanifest'). However, given evidence of posterior cortical atrophy in premanifest HD, we predicted visuomotor integration would be adversely affected, with greater impairment under conditions of indirect visual feedback. METHODS: 239 subjects with the HD CAG expansion, ranging from more than a decade before predicted clinical onset until early stage disease, and 122 controls, completed a circle-tracing task, which included both direct and indirect visual feedback conditions. Measures included accuracy, speed, and speed of error detection and correction. Using brain images acquired with 3T magnetic resonance imaging (MRI), we generated grey and white matter volumes with voxel-based morphometry, and analyzed correlations with circle-tracing performance. RESULTS: Compared with controls, early HD was associated with lower accuracy and slower performance in both circle-tracing conditions. Premanifest HD was associated with lower accuracy in both conditions and fewer rotations in the direct condition. Comparing performance in the indirect condition with the direct condition, HD gene expansion-carriers exhibited a disproportionate increase in errors relative to controls. Premanifest and early HD groups required longer to detect and correct errors, especially in the indirect condition. Slower performance in the indirect condition was associated with lower grey matter volumes in the left somatosensory cortex in VBM analyses. CONCLUSIONS: Visuomotor integration deficits are evident many years before the clinical onset of HD, with deficits in speed, accuracy, and speed of error detection and correction. The visuomotor transformation demands of the indirect condition result in a disproportionate decrease in accuracy in the HD groups. Slower performance under indirect visual feedback was associated with atrophy of the left-hemisphere somatosensory cortex, which may reflect the proprioceptive demands of the task.


Asunto(s)
Enfermedad de Huntington/complicaciones , Trastornos de la Destreza Motora/etiología , Trastornos de la Percepción/etiología , Adulto , Encéfalo/patología , Progresión de la Enfermedad , Femenino , Humanos , Enfermedad de Huntington/patología , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Trastornos de la Destreza Motora/complicaciones , Trastornos de la Destreza Motora/patología , Fibras Nerviosas Mielínicas/patología , Pruebas Neuropsicológicas , Trastornos de la Percepción/complicaciones , Trastornos de la Percepción/patología , Valor Predictivo de las Pruebas , Estadística como Asunto
10.
J Neuropsychiatry Clin Neurosci ; 22(2): 196-207, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20463114

RESUMEN

Huntington's disease has been linked with fronto-subcortical neuropathology and behaviors consistent with this dysfunction. Little is known about these "frontal" behaviors in the earliest phase of the illness. Comparisons between participants in the Predict-HD study (745 "expansion-positive" and 163 "expansion-negative" control subjects) on the Frontal System Behavior Scale looked for evidence of frontal behaviors, including apathy, disinhibition, and executive dysfunction. The authors were also able to compare participant and companion reporting of these frontal behaviors as a possible indication of awareness of behaviors. Expansion-positive individuals reported significantly more of these frontal behaviors than expansion-negative peers. Self- and companion-reported frontal behaviors were related to other Huntington's disease markers. Expansion-positive participants closest to Huntington's disease diagnosis showed greater discrepancies with companions on ratings of frontal behaviors. Even though most are more than 10 years from Huntington's disease diagnosis, mild frontal behaviors were present in this prediagnosed sample, which might make these behaviors useful as markers for Huntington's disease onset. Participant/companion discrepancies, especially closest to Huntington's disease diagnosis, might suggest early lack of awareness in these individuals.


Asunto(s)
Enfermedad de Huntington/diagnóstico , Enfermedad de Huntington/psicología , Trastornos Mentales/diagnóstico , Trastornos Mentales/psicología , Adulto , Cuerpo Estriado/patología , Progresión de la Enfermedad , Femenino , Humanos , Enfermedad de Huntington/patología , Estudios Longitudinales , Masculino , Trastornos Mentales/patología , Tamaño de los Órganos , Probabilidad , Pronóstico , Escalas de Valoración Psiquiátrica , Autoimagen , Índice de Severidad de la Enfermedad , Factores de Tiempo
11.
J Math Psychol ; 54(1): 28-38, 2010 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-20419064

RESUMEN

Chronic cannabis users are known to be impaired on a test of decision-making, the Iowa Gambling Task (IGT). Computational models of the psychological processes underlying this impairment have the potential to provide a rich description of the psychological characteristics of poor performers within particular clinical groups. We used two computational models of IGT performance, the Expectancy-Valence Learning model (EVL) and the Prospect-Valence Learning model (PVL), to assess motivational, memory, and response processes in 17 chronic cannabis abusers and 15 control participants. Model comparison and simulation methods revealed that the PVL model explained the observed data better than the EVL model. Results indicated that cannabis abusers tended to be under-influenced by loss magnitude, treating each loss as a constant and minor negative outcome regardless of the size of the loss. In addition, they were more influenced by gains, and made decisions that were less consistent with their expectancies relative to non-using controls.

12.
Mov Disord ; 24(12): 1763-72, 2009 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-19562761

RESUMEN

The PREDICT-HD study seeks to identify clinical and biological markers of Huntington's disease in premanifest individuals who have undergone predictive genetic testing. We compared baseline motor data between gene-expansion carriers (cases) and nongene-expansion carriers (controls) using t-tests and Chi-square. Cases were categorized as near, mid, or far from diagnosis using a CAG-based formula. Striatal volumes were calculated using volumetric magnetic resonance imaging measurements. Multiple linear regression associated total motor score, motor domains, and individual motor items with estimated diagnosis and striatal volumes. Elevated total motor scores at baseline were associated with higher genetic probability of disease diagnosis in the near future (partial R(2) 0.14, P < 0.0001) and smaller striatal volumes (partial R(2) 0.15, P < 0.0001). Nearly all motor domain scores showed greater abnormality with increasing proximity to diagnosis, although bradykinesia and chorea were most highly associated with diagnostic immediacy. Among individual motor items, worse scores on finger tapping, tandem gait, Luria, saccade initiation, and chorea show unique association with diagnosis probability. Even in this premanifest population, subtle motor abnormalities were associated with a higher probability of disease diagnosis and smaller striatal volumes. Longitudinal assessment will help inform whether motor items will be useful measures in preventive clinical trials.


Asunto(s)
Enfermedad de Huntington/diagnóstico , Enfermedad de Huntington/fisiopatología , Actividad Motora/fisiología , Adulto , Distribución de Chi-Cuadrado , Cuerpo Estriado/patología , Femenino , Pruebas Genéticas/métodos , Humanos , Enfermedad de Huntington/genética , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Actividad Motora/genética , Pruebas Neuropsicológicas , Probabilidad , Análisis de Regresión , Estudios Retrospectivos , Repeticiones de Trinucleótidos/genética
13.
J Clin Psychiatry ; 69(11): 1758-65, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19012814

RESUMEN

OBJECTIVE: Obsessive and compulsive symptoms (OCS) are more prevalent in patients with diagnosed Huntington's disease (HD) than in the general population. Although psychiatric symptoms have been reported in individuals with the HD gene expansion prior to clinical diagnosis (pre-HD), little is known about OCS in this phase of disease. METHOD: The goal of this study was to assess OCS in 300 pre-HD individuals and 108 non-gene-expanded controls from the Neurobiological Predictors of Huntington's Disease (PREDICT-HD) study (enrolled between November 2002 and April 2007) using a multidimensional, self-report measure of OCS, the Schedule of Compulsions, Obsessions, and Pathologic Impulses (SCOPI). Additionally, pre-HD individuals were classified into 3 prognostic groups on the basis of age and CAG repeat length as "near-to-onset" (< 9 estimated years to onset), "mid-to-onset" (9-15 years to onset), and "far-to-onset" (> 15 years to onset). We compared the 3 pre-HD groups to the controls on SCOPI total score and 5 subscales (checking, cleanliness, compulsive rituals, hoarding, and pathologic impulses), controlling for age and gender. RESULTS: All models showed a significant (p < .05) group effect except for hoarding, with an inverted-U pattern of increasing symptoms: controls < far-to-onset < mid-to-onset, with the near-to-onset group being similar to controls. Although the mid-to-onset group showed the most pathology, mean scores were below those of patients with diagnosed obsessive-compulsive disorder. SCOPI items that separated pre-HD individuals from controls were focused on perceived cognitive errors and obsessive worrying. CONCLUSION: Subclinical OCS were present in pre-HD participants compared to controls. The OCS phenotype in pre-HD may present with obsessive worrying and checking related to cognitive errors and may be a useful target for clinical screening as it could contribute to functional status.


Asunto(s)
Conducta Compulsiva/epidemiología , Enfermedad de Huntington/diagnóstico , Enfermedad de Huntington/epidemiología , Conducta Obsesiva/epidemiología , Adulto , Estudios de Casos y Controles , Comorbilidad , Estudios Transversales , Femenino , Humanos , Masculino , Prevalencia , Modelos de Riesgos Proporcionales , Riesgo
14.
Mov Disord ; 23(13): 1830-6, 2008 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-18785217

RESUMEN

Longitudinal studies of neurocognitive function in prediagnosis Huntington disease (pre-HD) have been few, and duration of follow-up has been brief. In this study, 155 individuals at-risk for HD completed a battery of cognitive and motor tasks at two study visits approximately 10 years apart. Participants were classified as: (1) at-risk, without the CAG expansion (healthy controls, NC; n = 112), or (2) CAG expanded (CAG+; n = 43). To examine the rate of decline at different stages of the pre-HD period, participants in the CAG+ group were further characterized as converters (i.e., individuals who developed manifest HD over the course of the study; n = 21) or nonconverters (n = 22), and their performances were compared. The CAG+ group exhibited faster rates of neurocognitive decline over the course of the study, relative to the NC group. In addition, more rapid decline was associated with closer proximity to estimated age of disease onset in the CAG+ group. Faster rates of motor and psychomotor decline were observed in the CAG+ converter group, relative to the nonconverters. These findings suggest that neurocognitive decline in pre-HD, particularly in motor and psychomotor domains, begins insidiously and accelerates as individuals approach disease onset.


Asunto(s)
Cognición/fisiología , Enfermedad de Huntington/diagnóstico , Enfermedad de Huntington/fisiopatología , Actividad Motora/fisiología , Adulto , Edad de Inicio , Femenino , Humanos , Enfermedad de Huntington/genética , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Desempeño Psicomotor/fisiología , Tiempo de Reacción/genética , Índice de Severidad de la Enfermedad , Expansión de Repetición de Trinucleótido/genética
15.
Cogn Behav Neurol ; 20(4): 212-8, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18091069

RESUMEN

OBJECTIVE: To characterize neurocognitive signs of disease progression in prediagnosis and early Huntington disease (HD) and compare the sensitivity of 2 disease staging classification schemes for detecting these signs. METHODS: Three hundred and six individuals at-risk for or recently diagnosed with HD completed the Unified Huntington's Disease Rating Scale, genetic testing, and a neurocognitive battery. Two schemes were used to estimate latency to onset of disease. One was based on genetic information (CAG repeat length) and the other was based on the extent of motor signs. Effect sizes were compared to assess the relative sensitivity of the 2 schemes for detecting signs of disease progression. RESULTS: CAG-expanded participants far from estimated diagnosis performed similarly to controls, whereas those near to estimated diagnosis were impaired relative to controls. Overall, the method employing genetic information yielded larger effect sizes than the motor scheme, particularly for strategic and executive function measures; the motor scheme resulted in a larger effect size for a measure of motor/psychomotor function. CONCLUSIONS: Neurocognitive function is not uniformly affected in prediagnosis and early HD; individuals near to their estimated age of diagnosis have cognitive signs similar to HD, whereas individuals far from estimated diagnosis appear cognitively normal. Classification schemes that incorporate both genetic and phenotypic information may be more sensitive for tracking neurocognitive signs of disease progression.


Asunto(s)
Trastornos del Conocimiento/diagnóstico , Enfermedad de Huntington/diagnóstico , Pruebas Neuropsicológicas/estadística & datos numéricos , Adulto , Trastornos del Conocimiento/genética , Diagnóstico Precoz , Femenino , Predisposición Genética a la Enfermedad/genética , Pruebas Genéticas , Humanos , Proteína Huntingtina , Enfermedad de Huntington/genética , Masculino , Persona de Mediana Edad , Proteínas del Tejido Nervioso/genética , Examen Neurológico , Proteínas Nucleares/genética , Fenotipo , Psicometría , Valores de Referencia , Repeticiones de Trinucleótidos
16.
J Int Neuropsychol Soc ; 12(5): 668-76, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16961948

RESUMEN

Asperger's disorder (ASP), like other autism spectrum disorders, is associated with altered responsiveness to social stimuli. This study investigated learning and responsiveness to nonsocial, but motivational, stimuli in ASP. We examined choice behavior and galvanic skin conductance responses (SCRs) during the Iowa Gambling Task (IGT; Bechara et al., 1994) in 15 adolescents and young adults with ASP and 14 comparison subjects. We examined aspects of learning, attention to wins and losses, and response style with a formal cognitive model, the Expectancy-Valence Learning model (Busemeyer & Stout, 2002). The ASP group did not differ from the comparison group in proportions of selections from advantageous decks. However, ASP participants showed a distinct pattern of selection characterized by frequent shifts between the four IGT decks, whereas comparison participants developed clear deck preferences. SCR results showed some evidence of reduced responsiveness in the ASP group during the IGT. Results from the cognitive model indicated that, in contrast to the comparison group, the ASP group's selections were less consistent with the motivational significance they assigned to decks. Findings are discussed in the context of the neurobiological substrates associated with IGT performance.


Asunto(s)
Síndrome de Asperger/fisiopatología , Síndrome de Asperger/psicología , Conducta de Elección , Respuesta Galvánica de la Piel/fisiología , Motivación , Adolescente , Análisis de Varianza , Atención/fisiología , Cognición/fisiología , Femenino , Humanos , Masculino , Memoria/fisiología , Pruebas Neuropsicológicas/estadística & datos numéricos
17.
Mem Cognit ; 34(3): 556-67, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16933765

RESUMEN

In two experiments, we examined the representation, treatment, and attention devoted to the members of reference (i.e., club members) and nonreference (i.e., not club members) categories. Consistent with prior work on category interrelatedness (e.g., Goldstone, 1996; Goldstone, Steyvers, and Rogosky, 2003), the findings reveal the existence of asymmetric representations for reference and nonreference categories, which, however, decreased as expertise and familiarity with the categories increased (Experiments 1 and 2). Participants also more readily judged two reference exemplars as being the same than they did two nonreference exemplars (Experiment 1) and were better at detecting reference than nonreference exemplars in a set of novel, category-unspecified exemplars (Experiment 2). These findings provide evidence for the existence of a feature asymmetry in the representation and treatment of exemplars from reference and nonreference categories. Membership in a reference category acts as a salient feature, thereby increasing the perceived similarity and detection of faces that belong in the reference, in comparison with the nonreference, category.


Asunto(s)
Discriminación en Psicología , Percepción , Percepción Visual , Humanos , Aprendizaje , Detección de Señal Psicológica
18.
J Pers Soc Psychol ; 82(3): 300-13, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11902618

RESUMEN

A distributed connectionist network can account for both bookkeeping (M. Rothbart, 1981) and subtyping (M. B. Brewer, V. Dull, & L. Lui, 1981; S. E. Taylor, 1981) effects. The finding traditionally regarded as demonstrating subtyping is that exposure to moderate (compared with extreme) disconfirmers leads to subsequent ratings of the group that are less stereotypic. Despite learning that is incremental and analogous to bookkeeping, the simulations replicate this finding and suggest that the "subtyping" pattern of results will be drastically reduced if disconfirmers are encountered before the stereotype is well-established. This novel prediction holds with human participants and offers a tantalizing suggestion: Although moderate disconfirmers may produce more stereotype change. stereotype development might be discouraged by exposure to either extreme or moderate disconfirmers.


Asunto(s)
Aprendizaje , Redes Neurales de la Computación , Estereotipo , Análisis de Varianza , Humanos , Indiana , Modelos Psicológicos
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